Trichotillomania (TTM) is a chronic impulse-control disorder involving the repetitive pulling and removal of one's hair that results in notable hair loss. A growing body of research has noted the public health significance of the disorder. TTM can result in a variety of debilitating physical, psychosocial, occupational and educational consequences. Empirical support for the efficacy of both pharmacological and nonpharmacological interventions for TTM is extremely limited, and there is growing recognition that traditional behavior therapy alone is likely insufficient. At a scientific meeting jointly sponsored by the National Institutes of Mental Health and the Trichotillomania Learning Center (http://www.nimh.nih.gov/scientificmeetings/trichotillomania.pdf), the paucity of treatment outcome research on TTM was noted and a specific recommendation made for researchers to conduct "larger randomized clinical trials to evaluate enhancement to current behavior therapy relative to treatment as usual..." To guide the enhancement of behavior therapy procedures, research on the psychopathology of TTM has discovered at least two distinct processes that may underlie the disorder. These include a habitual or "automatic" process and an emotional/cognitive regulatory or "focused" process. Preliminary feasibility and pilot studies conducted by the PI suggest that a treatment designed to address both of these processes (Acceptance-Enhanced Behavior Therapy for TTM;AEBT-T) may be an effective intervention for adults with the disorder. The current application proposes to compare a 10 session manualized version of AEBT-T to a manualized psychoeducation and supportive therapy (PST) in adults with TTM. Primary outcome variables will be assessed by blind independent evaluators, using a multi-element assessment battery. The relative efficacy of AEBT-T and PST for alleviating TTM-related distress and impairment will also be assessed, and treatment gains will be monitored over a six month follow-up. The primary aim of this study is to compare the benefits of AEBT-T to PST for reducing TTM severity in 84 children and adults (age 18-65) with TTM over a 12-week (10 session) acute treatment period. A secondary aim of the study is to examine the durability of both treatments in acute-phase treatment responders over a 6-month follow-up interval. In addition, a number of exploratory analyses are proposed to explore potential predictors of treatment response. Trichotillomania (TTM) is a disorder that has negative physical, social, occupational, academic and psychological effects. Despite its profound consequences, there exists no well-supported empirically based intervention to treat those with the disorder. The current study addresses the mission of the NIMH by determining if children and adults with TTM can benefit from behaviorally oriented treatment to decrease pulling severity and related distress.